ACCUMULATED OTHER COMPREHENSIVE LOSS - Summary of accumulated other comprehensive income (loss) (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ 128,468,076	$ 74,977,847
Comprehensive income	7,520,432	2,108,877
Ending balance	147,576,211	128,468,076
Unrealized loss in investments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(373,582)
Other comprehensive income loss before reclassification	83,768
Comprehensive income	83,768
Ending balance	(289,814)	(373,582)
Defined Benefit Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	100,569
Other comprehensive income loss before reclassification	42,115
Amounts reclassified from other comprehensive income (loss)	(125,526)
Comprehensive income	(83,411)
Ending balance	17,158	100,569
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(273,013)	(313,665)
Other comprehensive income loss before reclassification	125,883
Amounts reclassified from other comprehensive income (loss)	(125,526)
Comprehensive income	357
Ending balance	$ (272,656)	$ (273,013)